Chapter 96 - Unusual carotid artery conditions Flashcards
(45 cards)
Nonatherosclerotic causes of cerebrovascular symptoms
1) carotid kinking/coiling
2) carotid aneurysms
3) dissections
4) FMD
5) radiation arteritis
6) GCA
7) takayasu arteritis
8) cardiac embolization
9) carotid sinus syndrome
10) moyamoya
Carotid sinus syndrome
1) hypersensitivity of carotid sinus to daily life
2) syncopal symptoms 35% lifetime risk
3) reflex brady and hypotension
Carotid sinus hypersensitivity
bradycardia or hypotension to carotid sinus massage
3 types of carotid sinus hypersensitivity
1) carotid sinus hyperactivity: ventricular pause > 3 sec
2) asodepressor carotid sinus hyperactivity: BP drop > 50 mmHg without bradycardia
3) mixed
Treatment for 1 = pacing
treatment for 2 = drugs
Afferent signal from carotid sinus via this nerve
Glossopharyngeal and vagus
Efferent signal to heart and blood vessels for BP control
vagus
Symptoms of carotid sinus hypersensitivity
presyncope/syncope
1) abnormal sensorium
2) vision changes
3) parethesia
4) paresis
5) cognitive dysfunction
provocative maneuver = head turning, age, tight neck collars
Carotid sinus massage
1) upright position
2) monitor ECG adn BP
3) 5-10 s massage of one side
4) anterior margin of SCM at cricoid cartilage level
5) repeat on opposite side
6) if response then atropine then continue to determine extent needed
Treatment for carotid sinus hypersensitivity
1) fluid + salt intake, avoid physical maneuvers
2) midodrine
3) SSRI
4) fludrocortisone
5) norepinephrine
6) PM (DDD)
7) surgery: adventitial stripping
Moyamoya first described
Suzuki and Takaku 1969
Define moyamoya disease (MMD)
chronic, idiopathic, progressive cerebrovascular disease with ICA stenosis and occlusion
1) abnormal vascular network at brain base
2) more in east asian
3) prevalence 0.35-2.3/100000
4) 5-15 yo and 30-40 yo bimodal
5) more in females
symptom of MMD in children
1) paroxysmal hemiplegia
2) paresthesia
3) facial paralysis
4) paroxysmal headache
5) fine involuntary movement of extremity
6) progressive mental impairment
Symptom of MMD in adults
1) sudden disturbance of consciousness
2) intracranial hemorrhage
3) bleeding into ventricle
4) subarachnoid hemorrhage
Autoimmune disease associated with MMD
Graves
Familial form of MMD consist of this percentage
10%
autosomal dominant inheritance with low penetrance
Etiology of sporadic MMD
1) infectious
2) autoimmune
3) protein abnormality
4) genetic
Genetic loci of MMD
1) 3p24-26
2) 8q23
3) 6q25
4) 17q25 (RNF213)
5) 10q23.31
Pathophysiology of MMD
1) fibrocellular thickening of intima
2) SMC accumulation
3) stenosis to occlusion
4) HIF-1, VEGF, TGFB, hepatocyte GF, MMP expression
5) collateralization with Moyamoya vessels
Moyamoya vessels
1) thin media
2) fibrin deposit in vessel wall
3) fragmented elastic laminae
4) increase tendency to form microaneurysms
Suzuki and Takaku grading of MMD
Stage 1: narrowing or carotid fork
Stage 2: Moyamoya vessels, dilation of intracerebral main artery, no collateral from ECA
Stage 3: moyamoya affect MCA and ACA
Stage 4: moyamoya minimized with occlusion of ICA to level of Pcom
Stage 5: main ICA disappear, even less moyamoya
Stage 6: moyamoya and ICA totally gone
Treatment of moyamoya
1) avoid hyperventilation/exercise
2) anti HTN, lipid, DM, smk, wt loss, stop OCP
3) surgery: direct superficial temporal to MCA
4) surgery indirect pial synangiosis (temporal artery secured onto pia)
not antiplatelet - high risk of bleed
ICA coiling definition
Elongation and redundancy resulting in S shaped curvature
not clinically relevant stenosis on its own
ICA kinking degree
Mild > 60 degrees
Moderate 30-60 degrees
Severe < 30 degrees
associated with neuro symptoms 4-20%
epidemiology of carotid kinking/coiling
incidence 24.6%
female 70.6%
> 60 years old
kinking 56%
tortuosity 38%
coiling 6%
